In the design of an integrated circuit, standard cells having predetermined functions are used. Pre-designed layouts of standard cells are stored in cell libraries. When designing an integrated circuit, the pre-designed layouts of the standard cells are retrieved from the cell libraries and placed into one or more desired locations on an integrated circuit layout. Routing is then performed to connect the standard cells with each other using metal lines. The integrated circuit layout is thereafter used to manufacture the integrated circuit using a predetermined semiconductor manufacturing process.